The owner of the South Korean ferry that capsized last week with the loss of scores of lives is facing increased scrutiny, with investigators discovering that the vessel was overloaded, had recently been modified and was possibly crewed by insufficiently trained personnel.

The Wall Street Journal reports that the Sewol was loaded with 3,608 tons of cargo on its final journey — over three times more than the maximum recommended weight of 987 tons.

After acquiring the Sewol in 2012, operators Chonghaejin Marine Co. added 240 additional cabins, increasing passenger capacity by more than 150 people but also raising the vessel’s weight by almost 240 tons. It has also been established that the ferry was being operated despite a request made by the captain on April 1 for repairs to the steering gear.

The Sewol began listing sharply at around 9 a.m. last Wednesday, after making a sharp turn just outside Jindo Island, on its way from the city of Incheon to the resort island of Jeju. Within two hours, the ship — carrying 476 passengers, the majority of which were high school students going on a field trip — was submerged. Besides the 174 passengers rescued on the first day, no survivors have been found. The confirmed death toll hit at least 171 on Thursday, and the remaining missing passengers are feared dead.

On Wednesday, prosecutors raided the offices of Chonghaejin and the residence of Yoo Byung-eun, head of the family that controls the company, as well as premises belonging to corporate affiliates and an evangelical church in which he is believed to have an interest. Known as the “millionaire with no face” because of his rare public appearances, Yoo is a notorious figure in South Korea, having been jailed for fraud for four years in the early 1990s and allegedly previously leading a religious cult. In 1987, over 30 people from a sect committed mass suicide, but prosecutors found no evidence linking Yoo.

According to Chonghaejin’s audit report for last year, the company spent just $521 on crew training, including evacuation drills. By comparison, a competitor, Daea Express Shipping, spent 20 times that amount.

Among the 29 crew members on board the Sewol on its ill-fated journey, 20 people, including the captain, have been arrested or detained on charges of negligence and abandoning the passengers. Although crew members claimed that it was impossible to launch lifeboats while the Sewol was sinking, photos show a coast-guard officer managing the task during the initial rescue efforts. It has also emerged that the first distress call to authorities came from a student on board, not a member of the crew and that the 25-year-old third officer who was at the helm when the incident happened had never commanded the ship on this particularly dangerous stretch before.

Meanwhile, divers are making a concerted push to recover more bodies from the vessel in advance of adverse weather expected on Friday. Three large cranes are positioned near the scene, but a salvage operation of the 6,825-ton ferry is on hold until relatives of the missing passengers give their consent.

The tragedy is the worst maritime disaster in over two decades in South Korea and has evoked sympathy from all over the world — even from the country’s longtime nemesis North Korea. A spokeswoman for the South Korean Unification Ministry quoted a message from Pyongyang, which said “We express condolences for the missing and dead, including young students, from the sinking of the Sewol.”

Son Byoung-gi, a lawyer representing Chonghaejin Marine Co., has said the company will announce its position after the investigation is completed, adding that “if there is any legal responsibility, the owners are willing to offer their wealth and assets to help compensate the [families of the] victims.”

Correction: The original version of this story misstated that Yoo Byung-eun was the owner of Chonghaejin Marine Co. He is the head of the family that controls the company.

Clarification: South Korean media reported that Yoo Byung-eun led a religious cult responsible for a mass suicide in 1987. He denies any links to the group.